Pipe manufacture



Oct. 2 ,.1923. 1,469.206

T. P. ANTHONY PIPE MANUFACTURE Filed Feb. 21. 1922 a Sheets-Sheet 1 Elunmtinr:

Oct. 2, 1923. 1,469,206

T. P. ANTHONY P IPE MANUFACTURE Filed Feb. 21.. 1922 3 Sheets-Sheet 3 Patented Oct. 2, 1923.

UNITED STATES v 1,469,206 PATENT OFFICE.

memes PEACOCK ANTHONY, or EDGEWATER PARK, NEW JERSEY.

PIPE MANUFACTURE.

Application filed February 21, 1922. Serial No. 538,238.

. to the accompanying drawings.

As hereinafter described, my invention may be applied wlth particular advantage to pipes formed by what are known as centrifugal processes. In such processes, a cy lindrical mold is rotated while molten iron is poured therein so that the so-called centrifugal force which rotation develops in a revolving mass, compels the molten iron to line itself in a shell of uniform thickness-on the inside of the rotating mold. Ordina- 'rily, such molds are water cooled upon their exterior, with the result that the iron cast therein is chilled upon its outer surface to a depth of "approximately one thirty-second of an inch; necessitating a subsequent annealing process to soft/en the surface of the pipe, which is thus hardened. Moreover, pipe thus cast is of much denser composition and far more resistant to stresses than pipe cast in ordinary sand molds, but is more rapidly corroded by moisture; the difference in that respect beingprobably due to the characteristic change in the composition of the metal of the pipe which is incident to the centrifugal method of casting the same; for instance, metal from the same heat cast centrifugally and in ordinary sand molds shows upon. analysis the following differences in proportions of five of the ingredients thereof:

Therefore, the unquestionable advantages of centrifugal cast iron pipe as compared with sand molded pipe with respect to the strength and initial, cost thereof are oflset by the necessity for annea ing the centrifugal cast pipe.

Therefore, it is an object and effect of myinvention to minimize. the cost of the re quired annealing, as as possible. Therefore, it istobe noted that the hardness of the outer surface of such castings is due to the fact that the quicker solidification and further cooling of the metal coming incontact with the cooled molds aforesaid causes the retention of much combined carbon and .thus prevents the formation of graphite in the portions of the casting thus chilled. The purpose and effect of the annealing herein contemplated is to convert the hard brittle cementite into particles of soft graphitic carbon and, incidentally t'o.eliminate some of the carbon in'combination with such oxygen as may reach it. However, the principal object and'efi'ect of the process herein contemplated is the graphitizing of the cementite at a temperature above the critical point A0, of the cast iron and, of course, below its temperature of solidification.

As hereinafter described such effect is attained by controlling the rate of cooling of the ccntrifugally cast pipe from its solidiliration point-'uintilit-is annealed; and preferably nra confined atmosphere 1n an annealing oven, to whlch said pipes are withdrawn from their respective molds, while at a temperature above 1000 F.

I As' hereinafter described, the annealing process above contemplated. is preferably effected by removing each centritugally cast pipe from its mold, axially, into the confined annealing atmosphere and rotating said pipe upon lts axis while progressing the latter transverselywith respect to its original position, into regions of successively lower temperature in said confined atmosphere until said pipe has cooled to less than 500 F and then withdrawing said pipe from said secluded atmosphere into the open atmosphere.

As hereinafter described, I find it convenient to employ an annealing oven having guide rollers to receive and support the pipe shifted axially into said oven, and aseries of rollers, mounted torotate upon axes paraallel with the axis of said pipe and arranged to successively engage said pipe and rotate it upon its axis while progressing the latter transversely with respectjo its originalvposition. Such an oven is conveniently provided with a source of heat whereby its'tenr perature may be-controlled and such that it may be maintainedat the proper high temperature at the region of introduction of said pipe. 7

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My invention includes the various novel features of construction and arrangement hereinafter more definitely specified. The rotary mold and its appurtenances herein disclosed are claimed in my copending application Serial No. 507,824, filed October 15, 1921, for Letters Patent of the United States.

Fig. I is a diagrammatic side elevation of a casting and annealing apparatus which may be conveniently used in accordance with my invention.

Fig. 11 is a diagrammatic vertical sectional view of the rotary mold and its appurtenances indicated in Fig. I.

Fig. 111 is a diagrammatic vertical sectional view of an annealing oven adapted to receive pipe removed axially from the apparatus shown in Fig. I, and including means for rotating such a pipe upon its axis while shifting the latter transversely, to the region of discharge from said oven.

in said figures; the pipe 1 is being formed by molten metal 2 poured through the spout 3 from the ladle 5 which is tiltable upon the pivot 6 at the outer end of said spout. Said pipe 1 is formed within the rotary mold comprising the inner shell 8 surrounded by insulating material 9 within the outer casing 10. Said casing 10 is provided with annular tracks 11 and 12 whereby said mold may be supported for rotation upon suitable rollers 13. Said mold may be rotated by a belt 14 encircling the belt flange 15, while the entire mold is axially shifted with respect to said spout3, which ma remain stationary. The exterior of said mo d may be chilled by water sprayed thereon from the pipe 17 within the water shield 18. Thedryqcomminuted lining material 20 may be sprayd within the said pipe 1 through the IlOZZll'Ql of the conduit 22 which maybe held stationary with said spout 3 while the application of the molten metal 2 and said lining material E in a helical path is determined by the relative axial movement of said pipe 1 with respect to'said spout 3 and conduit 22. Rot-ation of said mold may be conveniently effected by an electric motor 25 mounted upon a suitable carriage 26, provided with four supporting rollers 27 upon tracks 28 parallel with the axis of rotation of said pipe 1; while axial movement of said carriage 2G, and said pipe 1 rotating therein, may be effected by a hydraulic cylinder 30 engaging a plunger 31 attached to said carriage.

I find it desirable to. omit the vitreous lining from the bell end 34 of said pipe 1 as in-.

dicated in Fig. 11; for the reason that said bell end is used to retain molten lead poured therein to form a joint with the opposite end of a similar pipe, and such a joint is preferably made with the lead in direct contact with the iron. Therefore, I have shown in Fig. Hthe mold tube 35 arranged to hold raeasoa a core of insulatingmiaterial 36 in such positlon as to cover the inner surface of said pipe 1 at its bell portion 34 and thus .prevent the deposit of vitreous coating material 20 thereat.

The principal ingredient of the vitreous coating material aforesaid may be glass cullet =comminuted to a fineness varylng from that of powdered sugar to granulated sugar. Although a temperature in excess of 2000 F. may be required to fuse glass alone and in bulk; it fuses at a much lower temperature when thus comminuted and mixed with other ingredients to-form such vitreous coatings as are employed for lining cooking utensils. Such compositions are fusible throughout a range of 900 to 1500 F. and are-satisfactory for use as above described. I have found it convenien to spray such 'material upon the interior of the pipe 1 by means of compressed air at eighty pounds per square inch, because I have had such spraying means at hand. However, such comminuted lining material may be otherwise applied. For instance, it may be delivered through a perforated vibratory distributor, without an air blast. Moreover, as the specific gravity of such lining material is approximately 2.5;

it may be deposited upon the inflowing stream of molten iron and distributed by the latter; the centrifugal effect aforesaid forcing the molten metal outward and leaving the lining material at the inner surface of the pipe 1. The latter method of application has the advantage that it insures a deeper penetration of the vitreous material with respect to the pores of the metal at the inner surface of the pipe thus coated.

it have found itconvenient to rotate such centrifugal apparatus as indicated in Figs. I and H at the rate of 550 revolutions per minute and to effect the relative axial movement of the spout 3 and mold 8 at the rate of approximately two feet per-minute.

When a pipe of the desired thickness is thus centrifugally cast. in said mold and preferably while it is at a temperature above 1000 F.; it is removed from said mold, axially, into the confined atmosphere 39 Within the oven 40. Such removal may be effected by engaging the bell end of said pipe when it is presented by the castlng apparatus in the position nearest to said oven and permittingthe mold to be retracted by the hydraulic means above described while said pipe is shifted axially forward into said oven. To facilitate the introduction of said pipe 1 to said oven 40; the latter is provided with a series of rollers 41 mounted to rotate upon axes 42 at right angles to the axis of said pipe 1. Said pipe 1 is then rotated upon its axis to remove it from said rollers onto a series of rollers 43 which are mounted to rotate upon axes coincident with shafts 44: parallel with the axis of said pipe 1.

lit

Said rollers 43 are connected by gears 46 and turned by any suitable means, for instance, by a motor 47 having a shaft 48 provided with a worm 49 engaging the worm wheel 50 upon theinitial end shaft 44. Each of said rollers 43 has a recessed portion 52 and they are rotated in the direction of the arrows marked thereon in Fig. III so as to progress said pipe 1 transversely with respect to its orignial position into regions of successively lower temperature in said confined atmosphere 39, until said pipe has cooled to less than 500 F. and is annealed. Said pipe may then be withdrawn from the secluded atmosphere 39, through the opening in said oven 40 into the open atmosphere. I find it convenient to provide said oven 40 with an oil or gas burner 62 whereby said confined atmosphere 39 may be maintained at 'a temperature above 1000 F.; and pref.- erably above 1400 F atthe region of introduction of said pipe 1. The products of combustion from said burner 62 pass downwardly to the flue 64 through which they escape to the outer atmosphere.

It may be observed that the construction and arrangement above described are such that said atmosphere 39 is hottest at the region of introduction of said pipe and the temperature thereof decreases toward the right hand end of the oven, as shown in Fig. III, and the general construction and arrangement above described are such as to enable the operator to control the rate of cooling said pi'pe 1 from its solidification point until it is annealed.

It may be observed that said pipe 1 may be annealed to .what is termed black heart condition without any oxidizing means, in

much less time and-from a lower temperature, than is required for producing what 1s known as the white heart" condition thereof. However, said burner 62 may be constructed and arranged to produce an oxidizing flame, if it is desired that said pipe 1 shall be annealed to the white heart condition. In either case, it is essential that they temperature of said pipeshall be controlledand gradually reduced from .above the critical Ac point of the met-a1 of which they are cast; in order to graphitize the carbon at the outer surface of said pipe which otherwise would form hard brittle cementite. It ma be observed that the white heart con ition of cast iron above contemplated is characterized by coarse fracture and structure of the metal, because of the high and ,prolonged heating to which it is exposed; so that castings in that condition are slightly weaker than when in the black heart condition. 1 I

It may also be observed that the presence of sulphur and manganese in the cast iron promotes the retention of combined carbon as hard cementite; whereas, the presence of which consists or malleabilizing above contemplated.

Although I have found the apparatus. above described convenient for the purpose set forth; I do not desire to limit myself to the specific construction and arrangement thereof, as it is obvious that various modifications may be made therein without departing from the essential features of my invention, as defined in the appended claims. For instance; the confined atmosphere to which the pipes are subjected during their annealing above contemplated may include any element adapted to facilitate the desired softening of their outer surfaces. Such material ma be directed to the pipe 1 from the conduit 65 shown in Fig. III; or, the pipe 1 may be temporarily encased in a container 67 with any decarbonizing material, forinstance, powdered iron ore 68 or other oxides. Or such a container 69 may hold inert refractory material 70, such as sand or clay, or diatomous earth, around the pipe 1 until the latter cools to the desired degree. Of course, the pipe 1 may be merely imbedded in suitable refractory material 70, during its cooling, annealing oven; the essential thing being that the heat in the pipe when-it is'cast shall not be permitted'to escape until the metal is annealed.

I claim:

1. The process of making cast iron pipe, in removing said cast pipe. from the mold. axially, into a confined atmosphere maintained at a temperature above 1400 F. at the region of introduction of said pipe; and while saidpipe is at a temperature above 1000 F.; rotating said pipe upon its axis while progressing the latter transversely with respect to its original position, intoregions of successively lower temperature in said confined atmosphere, until said pipe has cooled to less than 500 F and then withdrawing said pipe from ,said secluded atmosphere into the open atmosphere.

' 2. The process of making cast ironpipe, which consists in removing said cast pipe from the mold, into a confined atmosphere maintained at a temperature above 1400 F. at the region of introduction of said pipe; and while said pipe is at a tempera ture above 1000 F rotating said pipe upon its axis while progressing the latter transversely with respect to its original position, into regions of successively lower temperature in said confined atmosphere, until said pipe has cooled to less than 500 F.; and then withdrawing said pipe from said secluded atmosphere.

3. The process of making cast iron pipe, which consists in removingsaid cast pipe from the mold, into a confined atmosphere silicon and of large percentages of total I carbon facilitate the process of annealing without any cooled to less than 500 F.;

at the region of introduction of said pipe; and while said pipe is at a temperature above 1000 F; rotating said pipe upon its axis while progressing the latter transversely with respect to its original position, into regions of successively lower temperature in said confined atmosphere, until said pipe has cooled to less than 500 F; and then withdrawing said pipe from said secluded atmosphere.

4. The process of making cast iron pipe, which consists in removing said cast pipe from the mold, into a confined atmosphere maintained at a temperature above 1000 F. at the region of introduction of said pipe; and while said pipe is at a temperature above 1000 F.; progressing the pipe transversely with respect to its original position, into regions of successively lower temperature in said confined atmosphere, until said pipe has and then withdrawing said pipe from said secluded atmosphere.

5. The process of making cast iron pipe, which consists in removing said cast pipe from the mold, into a confined atmosphere maintained at a temperature above 1000 F. at the region of introductionof said pipe; and while said pipe is at a temperature above 1000 F.; progressing the pipe into regions of successively lower temperature in said confined atmosphere, until said pipe has cooled to less than 500 'F.; and then withdrawing said pipe from said secluded atmosphere. I

6. The process of making cast iron pipe, which consists in removing said cast pipe from the mold, into a confined atmosphere and while said pipe is at a temperature above its critical point Ac a progressing the pipe into regions of successively lower temperature in saidconfined atmosphere, until it has cooled below said point; and then withdrawing said pipe from said secluded atmosphere.

7. The process of making cast iron pipe, which consists in removing said cast pipe from the mold, into a confined atmosphere, and while said pipe is at a temperature above its critical point Ac and retaining said pipe in said confined atmosphere until it is annealed.

8. The process of making cast-iron pipe, which consists, in removing said pipe-from the mold, into a confined atmosphere and while said pipe is at a temperature above 1000 F.; and retaining said pipe in said atmosphere until it is annealed.-

9. The process of making cast iron pipe, which consists in rotating and controlling enace solidification point until it is annealed; by retarding the loss of the initial heat of fusion of said metal.

10. The process of making cast iron pipe, which consists in rotating a mold while pouring molten metal therein, until a pipe of the desired thickness is thus centrifugally cast in said mold; in contact with a rigid matrix in said mold, contemporaneously applying a vitreous lining material to the interior of said pipe, in a dry comminuted state, and thus forming a vitreous lining in said pipe; removing said cast pipe from said mold, into a confined atmosphere and while said pipe is at a temperature above its critical point; and retaining-said pipe in said confined atmosphere until it is annealed.

11. The process of forming a cast iron pipe with a vitreous lining, of less specific gravity than iron, which consists in delivering both molten iron and the lining material to the interior of a mold, with said lining material in a comminuted state, at a temperature below its fusing rotating said mold at such speed asto centrifugally distribute both said metal and lining material in said mold, until a pipe of the desired thickness is thus centrifugally cast in said mold, in contact with a rigid matrix in said mold; the inner surface of said pipe being at such temperature as to fuse the lining material; removing said cast pipe from said mold, into a confined atmosphere; and retaining said pipe in said confined atmosphere until it is annealed.

'12. The process of forming a cast iron pipe with a vitreous lining, of less specific gravity than iron, which consists in delivering both molten iron and the lining material to the interior of a mold, with said lining material in a comminuted state, at a temperature below its fusing point, while rotating said mold at such speed as to centrifugally distribute both said metal and Iiningmaterial in said mold, until a pipe of the desired thickness is thus centrifugally cast in said mold, in contact with a rigid matrix in said mold; the inner surface of said pipe being at such temperature as to fuse the lining material; and controlling the rate of cooling of said pipe from its solidification point until it is annealed.

In testimony whereof, I have hereunto signed my name at Burlington, New Jersey, this 18th da of February, 1922.

THOMXS PEACOCK ANTHONY.

Witnesses:

EVA T. Aanonson A. W. DRESSER.

point, while the rate of cooling of said pipe'from its 

